A case report of functional neurological symptom disorder mimicking autoimmune rhombencephalitis

ABSTRACT Functional neurological symptom disorder is often mistaken as autoimmune encephalitis despite not meeting the criteria for autoimmune encephalitis and overreliance on antibodies. We report the case of A 32-year-old woman had recurring headaches, dizziness, and double vision, despite normal laboratory results, neuroimaging, cerebrospinal fluid, and absence of focal neurological findings. Immunotherapy failed to provide lasting relief. A psychiatry consultation led to a diagnosis of functional neurological symptom disorder and subsequent treatment resulted in complete symptom resolution, with the patient remaining symptom-free at monthly follow-ups. Autoimmune encephalitis misdiagnosis can lead to unnecessary immunotherapies and delayed treatment. A psychiatrist’s involvement is vital to achieve an accurate diagnosis, provide appropriate counseling, and manage symptoms, thereby reducing the risk of harm from immunotherapies and ensuring a more efficient recovery.